"The Egyptian authorities have promised a fair trial," he said as allegations surfaced in a Cairo court on Wednesday that other journalists on trial alongside Greste had been tortured in prison.

The high-profile trial is seen as a test of the military-installed government's tolerance of independent media, with activists fearing a return to autocracy three years after the Arab Spring uprising that toppled dictator Hosni Mubarak.

"I ask you to free me on the guarantee from the Canadian embassy that I will not leave the country," he said.

Another defendant, Soheib Said, said he was "tortured by state security".

Without elaborating, he said he faced "physical and psychological torture" and had "asked to be checked [by a doctor] but nobody answered".

Before the hearing began, defendant Baher Mohamed shouted: "Journalists are not terrorists," as a bench full of security personnel separated those on trial from lawyers and reporters.

The hearing on Wednesday provided the first substantive look at the government's case. Prosecutors displayed a variety of seized items, such as cameras, cables and microphones, which they have described as evidence of the journalists' support for the Muslim Brotherhood. But they did not explain how possessing equipment commonly used for news gathering linked al-Jazeera's team to the Brotherhood.

Al-Jazeera has emphatically denied any wrongdoing on the part of its staffers. Greste, who was able to briefly speak with journalists from the courtroom cage, said it was clear the case was a political one.

Under questioning from Fahmy's lawyer, the lead investigator in the case cited no evidence other than employment by al-Jazeera to support the charge that Fahmy was a member of the Muslim Brotherhood. The investigator also conceded he was not aware that al-Jazeera English, which operates internationally, was editorially separate from the broadcaster's Egyptian branch, and from its Arabic-language service.

"I'm not a media expert," he said.

The journalists' case was adjourned until March 24.

Greste, winner of the prestigious Peabody award for a documentary on Somalia, told the first hearing on February 20 that justice would prevail.

His brother, Andrew, told AFP earlier on Wednesday that "Peter is obviously humbled and strengthened from the international support, and that's one of the things he thinks is keeping him safe in prison".

He said Greste, the only foreign defendant in custody, was in "good physical condition" and not "physically abused".

Mr Eihenbaums confirmed that Australia-born Greste, whose father is from Latvia, had registered as a Latvian in the 1990s as the Baltic nation broke free from the crumbling Soviet Union in 1991. Despite being registered and receiving a certificate of citizenship, he never formally collected his passport, Mr Eihenbaums said.

"He is a Latvian citizen. He registered as Latvian citizen in the 1990s. His father is a Latvian citizen, which automatically entitled him to citizenship," he added.

Mr Rinkevics and Australian Foreign Affairs Minister Julie Bishop agreed on Wednesday by telephone "to closely coordinate the activities of Latvian and Australian diplomatic services to have Peter Greste released as soon as possible", according to a Latvian foreign ministry statement.